


What he had to do.

by orphan_account



Category: Undertale (Video Game)
Genre: Angst, Angst with a Happy Ending, Insanity, Really not sure what tags to use for this, dusttale, i guess??
Language: English
Status: Completed
Published: 2018-12-17
Updated: 2018-12-17
Packaged: 2019-09-21 09:49:24
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 801
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17041466
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: Dusttale AUSans deals with his dwindling sanity after murdering the last monster he needed - his brother. Until he comes back to haunt Sans, encouraging him to continue and make the human suffer for their crimes.Sans begins to lose himself completely, over his guilt and his shattered sanity beyond repair. All he cares about now is killing the human as cruelly and horrifyingly as possible.





	What he had to do.

**Author's Note:**

> hi guys, not sure where i was going with this.
> 
> The dusttale AU is one of my favourites and I really love Sans’ character in the au, and i just really wanted to write something for him, especially what might have happened when Sans realised Papyrus was haunting him
> 
> so i came out with this!
> 
> points if you get the reference at the end c;
> 
> i hope you enjoy!!

Sans fell to his hands and knees, trembling and breathing hard. He stared blankly at the pile of dust that was now his brother. He stared and stared, trying feel something, _anything._ He just _murdered_ his baby brother in cold blood, and he felt nothing but the chill of the snow seeping into his bones.

He slowly reached forward and scooped up some of the dust, watching it slip through his shaking bones. He laughed quietly to himself, it was pained and forced. Leaning back on his knees, Sans looked up at the sparkling crystals acting as stars, feeling his eye sockets sting and his cheek bones become wet. He slapped a hand over his eye sockets, and laughed loudly, hysterically, and bitterly. 

“ha... haha... hahaha! what am i cryin’ for? idiot...” There was no sobs, no struggling for breath, no trembling, just the tears flowing freely and dripping into the snow. He didn’t feel sadness, regret, or guilt. In that moment he felt nothing. So why was he crying? This is what he had to do. He had to kill the human and this was the price. Maybe a previous version of himself was crying for him because he couldn’t any more.

“stupid.” Sans muttered to himself, slowly getting to his feet and taking one last look at his brother’s remains. He slowly picked up the dusty red scarf and he just held it for a long while, wondering if he really deserved to wear it after what he had done.

“Brother. Why are you sad?” Sans jumped hearing the voice behind him and threw out a wall of bones, whirling around ready to fight.

His eye sockets widened as he was greeted by the ghostly projection of his dead brother. He stepped back, clutching the red scarf against his rib cage and let out a startled yelp as he tripped, landing in a mixture of his brother’s dust and snow.

“y-you’re not real. you’re dead. i k-killed you, you can’t be r-real.” Sans whimpered softly, curling in on himself and covering his face with the scarf, his boney fingers curling tightly into the soft material. He was convinced he was hallucinating, that this phantom of his brother, Papyrus, was a manifestation of his guilt.

“you’re not real. you’re not real. you’re not real.” Sans repeated to himself over and over, ignoring how the spirit hovered next him looking concerned.

“Sans... Brother...” The ghost started to reach towards Sans.

“NO. DON’T TOUCH ME.” Sans screamed, throwing a blue bone at his ‘brother’ and trying to get away from it. The bone just phased through and landed in the snow with a _‘fwoomf’._

“i killed you, you’re dead! this dust over me, it’s yours! this is your scarf!” He held out the dusty, tattered scarf for emphasis. “i took the EXP from your death.”

The ghost stared at him, clearly considering what to say next. Papyrus moved slowly towards him, ignoring how he stepped back.

“I...want to help you. Like I said. I want to help you kill the human. You have to kill them. I am here for _you,_ brother, to help.” The ghost of Papyrus suddenly looked significantly less menacing to Sans, and his expression softened.

“p-pap, i-i...” Sans held back a sob. “i’m sorry, i’m so sorry. god, fuck, i-i didn’t wanna hurt you. i had to, i needed your strength. i didn’t want to hurt any of you. i’m so fucking sorry.”

Sans began to tremble, looking at his dust coated hands.

“I know. And that’s okay! You didn’t have a choice, brother. We know that you did what you felt was right. We want you to kill that human. Make them suffer for what they did to us, for what they have done to you.” Papyrus smiled reassuringly, hoping to make his brother understand that it was alright.

“yeah... yeah. i’ll kill ‘em. i’ll make ‘em suffer like they made us suffer. i’ll...i’ll make it so cruel they’ll never come back. th-then...I’LL reset the timeline and they’ll be gone forever, and...and everything’ll go back to normal.” Sans let out a shaky breath and finally felt it was okay to tie his brother’s scarf around his neck, so he did. 

“i’ll kill them. i’ll kill them! they’ll be just a pile of BONES when i’m finished with ‘em! we’re gonna kill them, paps!” He bent over, clutching his non existent stomach in laughter, growing louder and more hysterical. 

Calming down, he looked up at the ghost of his brother, holding his face with his fingers slightly curled into and around his eye sockets. His right socket went black while the left lit up a deep but bright purple, his grin widening as far as it could go.

“we’re gonna have a **MAD** time.”

**Author's Note:**

> thank you taking the time to read!! if you liked this please leave a kudos and a comment, thank you!!
> 
> the reference at the end for sans’ pose was this: https://goo.gl/images/irQb2X


End file.
